U.S. patent number 5,681,345 [Application Number 08/773,610] was granted by the patent office on 1997-10-28 for sleeve carrying stent.
This patent grant is currently assigned to Scimed Life Systems, Inc.. Invention is credited to Charles L. Euteneuer.
United States Patent |
5,681,345 |
Euteneuer |
October 28, 1997 |
Sleeve carrying stent
Abstract
A sleeve carrying stent for implantation within a body lumen
comprising a radially expandable cylindrical stent component having
an inner wall and an outer wall, a plurality of elongated support
struts, and a sleeve secured to the ends of the struts, wherein the
struts are preferably parallel and may be loosely interlocked with
the stent component, and wherein the stent component is able to
move longitudinally independent of the struts.
Inventors: |
Euteneuer; Charles L. (Sts.
Michael, MN) |
Assignee: |
Scimed Life Systems, Inc.
(Maple Grove, MN)
|
Family
ID: |
23568054 |
Appl.
No.: |
08/773,610 |
Filed: |
December 30, 1996 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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396639 |
Mar 1, 1995 |
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Current U.S.
Class: |
623/1.11;
606/194; 606/198 |
Current CPC
Class: |
A61F
2/07 (20130101); A61F 2/91 (20130101); A61F
2/915 (20130101); A61L 31/044 (20130101); A61L
31/048 (20130101); A61L 31/06 (20130101); A61L
31/048 (20130101); C08L 27/18 (20130101); A61L
31/06 (20130101); C08L 75/04 (20130101); A61L
31/06 (20130101); C08L 67/00 (20130101); A61L
31/06 (20130101); C08L 83/04 (20130101); A61F
2/852 (20130101); A61F 2002/075 (20130101); A61F
2002/825 (20130101); A61F 2002/9155 (20130101); A61F
2250/0063 (20130101); A61F 2/848 (20130101); A61F
2/90 (20130101); A61F 2220/0016 (20130101); A61F
2220/0075 (20130101); A61F 2230/0013 (20130101) |
Current International
Class: |
A61F
2/06 (20060101); A61L 31/04 (20060101); A61L
31/06 (20060101); A61M 029/00 () |
Field of
Search: |
;623/1,12
;606/191,192,194,195,198 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Buiz; Michael
Assistant Examiner: Rasche; Patrick W.
Attorney, Agent or Firm: Vidas, Arrett & Steinkraus
Parent Case Text
This is a continuation of application Ser. No. 08/396,639 filed on
Mar. 1, 1995 now abandoned.
Claims
What is claimed is as follows:
1. A sleeve carrying stent for implantation within a body lumen
comprising in combination:
a radially expandable cylindrical stent component having open ends,
an inner wall and an outer wall;
a plurality of elongated support struts, each of said plurality of
struts having a first end and a second end, said struts being
carried by the stent component, wherein the stent component is able
to move longitudinally independent of the struts; and
a biocompatible open ended tubular sleeve associated with the stent
component,
wherein the sleeve is positioned parallel with the stent component
and is secured to the struts; said sleeve carrying stent being
constructed and arranged for implantation and expansion with the
sleeve and struts incorporated with the stent.
2. A sleeve carrying stent as in claim 1 wherein the struts are
parallel with the stent component, the sleeve has a first end and a
second end, and the composition of the sleeve is chosen from a
group consisting of collagen, polytetrafluoroethylene, polyesters,
polyurethane and silicones.
3. A sleeve carrying stent as in claim 2 wherein the struts have a
longitudinal axis and further are loosely interlocked with the
stent component.
4. A sleeve carrying stent as in claim 3 wherein the struts are
loosely interlocked to the stent component at a point generally
equidistant from either end of the stent component.
5. A sleeve carrying stent as in claim 4 wherein the struts have
securing means, the ends of the sleeve being secured in placed by
the securing means, and wherein the length of the struts and the
sleeve remain substantially constant during the radial expansion of
the stent component.
6. A sleeve carrying stent as in claim 5 wherein the struts are
radially spaced and have substantially the same length as the stent
component in its collapsed form.
7. A sleeve carrying stent as in claim 6 wherein there are three
struts.
8. A sleeve carrying stent as in claim 7 wherein the struts have
radial perpendicular members extending from the ends of the struts,
the members having a rounded configuration around the longitudinal
axis of the strut.
9. A sleeve carrying stent as in claim 8 wherein the struts and the
sleeve are on the same side of the stent wall.
10. A sleeve carrying stent as in claim 2 wherein the struts have
securing means, the ends of the sleeve being secured in placed by
the securing means, and wherein the length of the struts and the
sleeve remain substantially constant during the radial expansion of
the stent component.
11. A sleeve carrying stent as in claim 10 wherein the struts are
radially spaced and have substantially the same length as the stent
component in its collapsed form.
12. A sleeve carrying stent as in claim 10 wherein there are three
struts.
13. A sleeve carrying stent as in claim 12 wherein the struts have
radial perpendicular members extending from the ends of the struts,
the members having a rounded configuration around the longitudinal
axis of the strut.
14. A sleeve carrying stent for implantation within a body lumen
comprising:
a radially expandable cylindrical stent component having open ends
an inner wall and an outer wall:
a plurality of elongated support struts carried by the stent
component parallel thereto, the struts being loosely interlocked
with the stent component, each of said plurality of struts having a
first end, a second end, a longitudinal axis, a central portion, a
depression, and tabs positioned approximately at the central
portion of the struts and on the opposite side of the stent wall
than that of the longitudinal axis of the struts, said tabs
projecting perpendicularly from the depression, wherein the stent
component is able to move longitudinally independent of the struts;
and
a biocompatible open ended tubular sleeve associated with the stent
component, said sleeve having a first end and a second end, wherein
the sleeve is positioned parallel with the stent component, the
composition of the sleeve being chosen from a group consisting of
collagen, polytetrafluoroethylene, polyesters, polyurethane and
silicones.
15. A sleeve carrying stent as in claim 14 wherein the struts are
loosely interlocked to the stent component at a point generally
equidistant from either end of the stent component.
16. A sleeve carrying stent as in claim 15 wherein the struts have
securing means, the ends of the sleeve being secured in placed by
the securing means, and wherein the length of the struts and the
sleeve remain substantially constant during the radial expansion of
the stent component.
17. A sleeve carrying stent as in claim 16 wherein the struts are
radially spaced and have substantially the same length as the stent
component in its collapsed form.
18. A sleeve carrying stent as in claim 17 wherein there are three
struts.
19. A sleeve carrying stem as in claim 18 wherein the struts have
radial perpendicular members extending from the ends of the struts,
the members having a rounded configuration around the longitudinal
axis of the strut.
20. A sleeve carrying stent as in claim 19 wherein the struts and
the sleeve are on the same side of the stent wall.
21. A sleeve carrying stent as in claim 14 wherein the struts have
securing means, the ends of the sleeve being secured in placed by
the securing means, and wherein the length of the struts and the
sleeve remain substantially constant during the radial expansion of
the stent component.
22. A sleeve carrying stent as in claim 21 wherein the struts are
radially spaced and have substantially the same length as the stent
component in its collapsed form.
23. A sleeve carrying stent as in claim 22 wherein there are three
struts.
24. A sleeve carrying stent as in claim 23 wherein the struts have
radial perpendicular members extending from the ends of the struts,
the members having a rounded configuration around the longitudinal
axis of the strut.
25. A sleeve carrying stent as in claim 24 wherein the securing
means are barbs positioned on the ends of the strut.
26. A sleeve carrying stent as in claim 24 wherein the struts and
the sleeve are on the same side of the stent wall.
27. A sleeve carrying stent as in claim 24 wherein the sleeve is
positioned on the opposite side of the stent wall than that of the
struts.
28. A sleeve carrying stent as in claim 27 wherein the struts are
on the outside of the stent wall.
29. A sleeve carrying stent as in claim 27 wherein the struts are
on the inside of the stent wall.
30. A sleeve carrying stent for implantation within a body lumen
comprising;
a radially expandable cylindrical stent component having a first
open end and a second open end, an inner wall and an outer
wall;
three elongated support struts, each of said struts having a first
end, a second end, a longitudinal axis and securing means, said
securing means comprising barbs positioned on the ends of said
struts, said struts further being carried by the stent component
and being loosely interlocked with the stent component at a point
generally equidistant from either end of the stent component, said
struts being radially spaced and having substantially the same
length as the stent component in its collapsed form, said struts
further having radial perpendicular members extending from the ends
of the struts, said members having a rounded configuration around
the longitudinal axis of the strut, and wherein the stent component
is able to move longitudinally independent of the struts, and the
length of the struts remains substantially constant during the
radial expansion of the stent component; and
a biocompatible open ended tubular sleeve associated with the stent
component, said sleeve having a first end and a second end, the
composition of said sleeve being selected from the group consisting
of collagen, polytetrafluoroethylene, polyesters, polyurethane and
silicones, and wherein the sleeve is positioned parallel with the
stent component, the ends of said sleeve being secured in place by
the barbs of the support struts, and the length of the sleeve
remains substantially constant during the radial expansion of the
stent component.
31. A sleeve carrying stent for implantation within a body lumen
comprising:
a radially expandable cylindrical stent component having a first
open end and a second open end, an inner wall and an outer
wall;
three elongated support struts, each of said struts having a first
end, a second end, a longitudinal axis and securing means, said
struts further being carried by the stent component and being
loosely interlocked with the stent component at a point generally
equidistant from either end of the stent component, said struts
being radially spaced and having substantially the same length as
the stent component in its collapsed form, said struts further
having radial perpendicular members extending from the ends of the
struts, said members having a rounded configuration around the
longitudinal axis of the strut, and wherein the stent component is
able to move longitudinally independent of the struts and the
length of the struts remains substantially constant during the
radial expansion of the stent component; and
a biocompatible open ended tubular sleeve associated with the stent
component, said sleeve having a first end and a second end, the
composition of said sleeve being selected from the group consisting
of collagen, polytetrafluoroethylene, polyesters, polyurethane and
silicones and wherein the sleeve is positioned parallel with the
stent component and on the opposite side of the stent wall than
that of the struts, the ends of said sleeve being secured in place
by the securing means of the support struts, and the length of the
sleeve remains substantially constant during the radial expansion
of the stent component.
32. A sleeve carrying stent as in claim 31 wherein the struts are
on the outside of the stent wall.
33. A sleeve carrying stent as in claim 31 wherein the struts are
on the inside of the stent wall.
34. A sleeve carrying stent for implantation within a body lumen
comprising:
a radially expandable cylindrical stent component having open ends,
an inner wall and an outer wall;
three elongated support struts, each of said struts having a first
end, a second end, a longitudinal axis, securing means comprising
barbs positioned on the ends of the struts, and radial
perpendicular members extending from the ends of the struts, the
members having a rounded configuration around the longitudinal axis
of the strut, said struts being carried by and parallel with the
stent component, said struts being radially spaced and having
substantially the same length as the stent component in its
collapsed form, the length of said struts remaining substantially
constant during the radial expansion of the stent component, and
wherein the stent component is able to move longitudinally
independent of the struts; and
a biocompatible open ended tubular sleeve associated with the stent
component, said sleeve having a first end and a second end, said
sleeve being positioned parallel with the stent component and
secured in place by the securing means of the struts, wherein the
length of said sleeve remains substantially constant during radial
expansion of the stent component, the composition of said sleeve
being selected from the group consisting of collagen,
polytetrafluoroethylene, polyesters, polyurethane and
silicones.
35. A sleeve carrying stent as in claim 34 wherein the struts and
the sleeve are on the same side of the stent wall.
36. A sleeve carrying stent for implantation within a body lumen
comprising:
a radially expandable cylindrical stent component having open ends,
an inner wall and an outer wall;
three elongated support struts, each of said struts having a first
end, a second end, a longitudinal axis, securing means, and radial
perpendicular members extending from the ends of the struts, the
members having a rounded configuration around the longitudinal axis
of the strut, said struts being carried by and parallel with the
stent component, said struts being radially spaced and having
substantially the same length as the stent component in its
collapsed form, the length of said shuts remaining substantially
constant during the radial expansion of the stent component, and
wherein the stent component is able to move longitudinally
independent of the struts; and
a biocompatible open ended tubular sleeve associated with the stent
component, said sleeve having a first end and a second end, said
sleeve being positioned parallel with the stent component and
secured in place by the securing means of the struts, said sleeve
being positioned on the opposite side of the stent wall than that
of the struts, wherein the length of said sleeve remains
substantially constant during radial expansion of the stent
component, the composition of said sleeve being selected from the
group consisting of collagen, polytetrafluoroethylene, polyesters,
polyurethane and silicones.
37. A sleeve carrying stent as in claim 36 wherein the struts are
on the outside of the stent wall.
38. A sleeve carrying stent as in claim 36 wherein the struts are
on the inside of the stent wall.
39. A sleeve carrying stent for implantation within a body lumen
comprising:
a radially expandable cylindrical stent component having open ends,
an inner wall and an outer wall;
a plurality of elongated support struts carried by the stent
component, wherein the struts are parallel and loosely interlocked
with the stent component, and wherein the stent component is able
to move longitudinally independent of the struts; and
an open ended tubular collagen sleeve associated with the stent
component, wherein the sleeve is positioned parallel with the stent
component, and is secured to the struts; said sleeve carrying stent
being constructed and arranged for implantation and expansion with
the sleeve and struts incorporated with the stent.
40. A sleeve carrying stent for implantation within a body lumen
comprising:
a radially expandable cylindrical stent component having open ends,
an inner wall and an outer wall;
a biocompatible open ended tubular sleeve, wherein the sleeve is
positioned parallel with the stent component; and
a plurality of elongated rod-shaped support struts incorporated in
the sleeve, wherein the struts are parallel with the stem
component, and wherein the stem component of the sleeve carrying
stent is able to move longitudinally independent of the sleeve;
said sleeve carrying stent being constructed and arranged for
implantation and expansion with the sleeve and struts incorporated
with the stent.
Description
FIELD OF THE INVENTION
This invention relates to a sleeve carrying stent which can be
surgically implanted inside of blood vessels or other related
lumen, and more particularly a conventional stent adapted to carry
a luminal collagen sleeve to a targeted area in an improved
manner.
BACKGROUND OF THE INVENTION
Vascular disease in man has become one of the primary causes of
overall poor health and death in recent years. Vascular diseases
occur throughout the body and affect the heart, limbs, and other
parts of the body. Arterial disease has caused death by heart
attack, reduced physical activity due to constriction or blockage
of vessels or arteries serving the muscles of the heart, and
constriction or blockage of vessels and arteries to the limbs.
These vascular diseases have resulted in the loss of extremities,
wherein the blood flow becomes sufficiently restricted to prevent
proper nourishment of the tissue of the extremities, and have
caused death when reduced blood flow to the muscles of the heart
starve the heart of needed blood.
Certain treatments for arterial diseases depend upon protheses or
vascular transplants for the purposes of returning proper levels of
blood flow to affected parts of the body. A variety of techniques
an protheses have been tried in an effort to provide a surgically
applied prosthesis capable of restoring proper blood flow to the
afflicted part of the body while at the same time repairing the
injured or affected part of the targeted area. Modern synthetic
fabric technology has provided prosthese such as collagen sleeves
which have been used as a substitute for diseased arteries and
vessels. Successful grafting of such fabric replacement prostheses
requires that coagulase tissue generated by the body become
implanted in the fabric prosthesis in order to ensure a successful
long-term graft. Tissue equivalents prepared from a hydrated
collagen lattice contracted by a contractile agent, such as
fiberblast cells or blood platelets to form the tissue equivalent
are disclosed in U.S. Pat. Nos. 4,485,096; 4,485,097; 4,539,716;
4,546,500; and 4,604,346. These tissue equivalents include, but are
not limited to, equivalents of epithelious tissue, connective
tissue, cartilage, bone, blood, organs, glands and blood vessels
and comprise living cells and extra cellular matrix molecules,
principally collagen, and may optionally be provided with
components now typically found in normal tissue.
The use of prostheses for the replacement of blood vessels and
other anatomical ducts is of great interest in medicine and
veterinary work. To be acceptable in a given application the
prosthesis must exhibit the proper mechanical properties and
bio-acceptable composition for the given application. For example,
vascular prostheses must provide a bio-acceptable surface which is
conducive to cellular attachment and sustained blood flow, yet is
strong enough not to split or tear. It is critical that the
vascular prosthesis not tear along the body of the prosthesis or at
the site of the sutures.
Collagen is an example of a bio-material which has many properties
desirable of medical prosthesis. The advantage of using collagen in
such devices is that collagen occurs naturally in the human body,
and the graft or protheses eventually absorbed into the tissue to
which is it attached. Collagen is usually found in the principal
protein component of the extra-cellular matrix. In mammals,
collagen sometimes constitutes as much as 60% of the total body
protein. It comprises most of the organic matter of skin, tendons,
bones, teeth, and occurs as fibrous inclusions in most of the body
structure. Collagen is a natural substance for cell adhesion and is
the major tensile load-bearing component of the muscular-skeletal
system. Collagen also has application in the manufacture of
implantable prostheses and the preparation of living tissue
equivalents.
Luminal collagen sleeves can be combined with conventional luminal
stents to repair and support damaged bodily vessels. The collagen
sleeve incorporates a non-thrombogenic surface and promotes growth
of endothelial cells, and can be used as a reservoir or point of
attachment for therapeutic agents. As the sleeve carrying stent
expands to support the targeted lumen, the collagen sleeve comes in
contact with the inner surface of the luminal wall. The contact
allows cellular growth between the wall of the lumen and the
collagen sleeve forming a bio-compatible vascular prosthesis. In
time, the sleeve and stent are incorporated into the wall of the
lumen, reinforcing and sealing the vessel, and allowing for normal
blood flow and bodily acceptability.
Stents are normally used in situations where part of the vessel
wall or stenotic plaque blocks or occludes blood flow in the
vessel. Normally a balloon catheter is utilized in a percutaneous
transluminal coronary angioplasty (PTCA) procedure to enlarge the
occluded portion of the vessel. However, the dilation of the
occlusion can form flaps, fissures and dissections which threaten
reclosure of the dilated vessel or even perforations in the vessel
wall. Implantation of stents can provide support for such problems
and prevent reclosure of the vessel or provide patch repair for a
perforated vessel. The stent overcomes the natural tendency of the
vessel walls of some patients to collapse, thereby maintaining a
more normal flow of blood through that vessel than would be
possible if the stent were not in place. When the stent is
positioned across the lesion, it is expanded, causing the length of
the tube to decrease and the diameter to expand. Depending on the
materials used in construction of the stent, the tube maintains the
new shape either through mechanical force or otherwise.
A problem that arises in using a conventional stent as a carrier
for a sleeve is the effect that the shortening of the stent during
expansion has on the sleeve itself. Sleeves are usually either
sutured onto the stent or are in direct contact with the stent. As
the stent radially expands after being located in the target area
it shortens in length, thus shortening the sleeve or even actually
tearing it because of the abrasive forces of the stent on the
sleeve. This creates a vascular prosthesis with undesirable
wrinkles and possible tears. This effect on the luminal sleeve
decreases the surface area which the sleeve was initially able and
intended to cover, and hinders the ability to predict the actual
spanning or placement of the sleeve. The wrinkles that result from
the shortening of the stent also have a negative effect on the
blood flow itself. When the stent is permanently placed in a
vessel, the continuous stress from the flow of the fluid along the
wrinkles within the vessel could cause internal turbulence
hindering normal blood flow.
It is desirable that replacements for vessels and arteries are
uniform in thickness, because thin portions of the wall may be
susceptible to rupture. The human body tends to compensate for
weaknesses in the walls of blood vessels and it has been proposed
that the unevenness will be compensated by tissue growth in the
weaker areas so that the interior surface of such a tube will
become uneven when the body attempts to compensate for weaknesses
in the tube wall at thin portions or nicks. This, of course,
produces a less than desirable final result since a smooth shiny
uniform interior wall is desired in the transplanted graft.
Wrinkles would tend to cause the same problem. During the period of
growth of the endothelial cells which contribute in the
incorporation of the sleeve into the tissue, the wrinkles can cause
uneven growth of tissue thus compounding the problem of smooth
blood flow through the sleeve.
The movement of the stent during expansion also can create abrasive
forces on sleeves that are not sutured onto the stent itself, but
are in direct contact with the stent causing possible tearing. It
is preferable to have a luminal sleeve delivery device which
maintains the length of the sleeve to create a smooth application
between the original vessel and the vascular prosthesis, and to
have a device in which the stent moves independent of the sleeve
preventing it from rubbing the sleeve or tearing it during
expansion. The longitudinal abrasion on the wall of the sleeve from
the shortening of the stent and the unpredictable coverage when
fully in place complicate the insertion of the vascular
prosthesis.
U.S. Pat. No. 5,236,447 discloses an artificial tubular organ
composed of a tubular supporting frame made of a plastic material
which is provided on at least one surface a medical prosthetic
material that comes in direct contact with the frame and lacks
independent movement. The frame is composed of a plurality of rings
arranged on an axis, and a plurality of connecting portions
extending between adjacent rings so as to connect them to each
other forming a cylindrical structure. The medical prosthetic
material may be a woven fabric, a knitted fabric, a nonwoven
fabric, or a combination thereof. Preferred fabric includes
absorbable macromolecular yarns and nonabsorbable macromolecular
yarns. This device is used as an artificial tubular organ for use
in substitution or reconstruction of tubular organs such as blood
vessels, tracheae and esophagi. The structure disclosed is a rigid,
noncollapsible structure making it difficult to insert in
cumbersome target areas.
U.S. Pat. No. 4,986,831 describes a homo graft composed of
collagenous tissue generated on a prosthetic device. A cylindrical
substrate is suspended by an anchoring device in the lumen of a
blood vessel allowing blood to flow over the inside as well as the
outside surfaces. One of the surfaces of the substrate is a
thrombogenic surface or supports a thrombogenic mesh material to
promote growth of a tube of collagenous tissue suitable for use as
a surgical graft. The body generates collagenous growth on the
surface of the substrate while the substrate is freely suspended in
the vessel. The substrate is not intended to remain in a particular
location. Therefore is not expandable and is removed from the
vessel after which a tubular homograft of collagenous tissue is
removed from the substrate to be used in some other location as
graft material.
U.S. Pat. No. 5,151,105 discloses a collapsible vessel sleeve for
implanting inside a live tissue fluid vessel and system. The sleeve
is directly connected to or in direct contact with a collapsible
circular stent to support the sleeve. A pair of linear stiffeners
are each sutured or otherwise loosely attached to opposite sleeve
exterior sides to maintain the length of the sleeve. The
collapsibility is accomplished by (1) initially skewing the tubular
graft toward its trailing end, and (2) compressing the circular
stents inwardly toward the catheter at the locations adjacent the
end points of connection of the longitudinal stiffeners to the
tubular body portion. Positioning wires are twisted onto and thus
removably attached to the stent at diametrically opposing points of
attachment about the cylindrical body portion. A capsule band is
wound around the sleeve and stent to maintain the collapsed sleeve
for travel to the target area, and is maneuvered into place by
means of the catheter and the guide wires. When the device is in
the targeted area the sleeve/stent is released and is urged into
place by the guide wires. Manipulation is required to precisely
position and fully expand the graft within the damaged lumen. The
surgeon needs to slightly agitate or reciprocate the positioning
wires to make the circular stents adopt positions in planes normal
to the axis of the vessel. When in place, the surgeon detaches the
positioning wires and removes the catheter device. A tacking system
can be used in order to secure the sleeve in the targeted lumen
area.
Difficulties have been encountered in the placement of sleeves into
targeted damaged vessels via a carrying stent. There is a need for
a sleeve carrying device that resists wrinkling or tears of the
sleeve during expansion of the stent, for a sleeve carrying stent
in which the stent moves independent from the sleeve to ensure
accurate placement, and is easy to insert into a predetermined
target area.
The art referred to and/or described above is not intended to
constitute an admission that any patent, publication or other
information referred to herein is "prior art" with respect to this
invention. In addition, this section should not be construed to
mean that a search has been made or that no other pertinent
information as defined in 37 C.F.R. .sctn.1.56(a) exists.
SUMMARY OF THE INVENTION
This invention relates to a novel sleeve carrying stent as well as
an improved way to incorporate biocompatible sleeves into damaged
vessels. More specifically it improves the installation of a
luminal sleeve while stabilizing the vessel via the expandable
stent. This device allows a stent, accompanied by a sleeve,
preferably made of collagen, to be placed in the target area,
maintaining tension and support of the sleeve while the stent
shortens during radial expansion.
The sleeve carrying stent is for implantation within a body lumen
and comprises a radially expandable cylindrical stent component
having an inner wall and an outer wall, a plurality of elongated
support struts, and a sleeve secured to the ends of the struts,
wherein the struts are preferably parallel and may be loosely
interlocked with the stent component, and wherein the stent
component is able to move longitudinally independent of the
struts.
It is an object of the present invention to provide an implantable
luminal sleeve that does not require major abdominal surgery in
order to effect implantation.
It is still another object to provide an implantable sleeve that
will maintain itself in a stable position after placement in a
patient.
It is another object of the invention to allow stent expansion
without altering the position or structural integrity of the
sleeve.
It is a further object of the present invention to provide a sleeve
carrying stent capable of being implanted simply and reliably.
Other objects, features, and characteristics of the present
invention, as well as the methods of operation and functions of the
related elements of the structure, and the combination of parts and
economics of manufacture, will become more apparent upon
consideration of the following description with reference to the
accompanying drawings, all of which form a part of this
specification.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows a side elevational view of the invention;
FIG. 2 shows a side elevational view of a conventional unexpanded
stent;
FIG. 3 shows a side elevational view of a strut;
FIG. 4 shows a top elevational view of a strut;
FIG. 5 shows a perspective view of a strut;
FIG. 6 shows a front elevational view of the configuration of the
struts when assembled as shown in FIG. 1;
FIG. 7 shows a sectional view along the line 7--7 in FIG. 1;
FIG. 8 shows a perspective view of a collapsed conventional
stent;
FIG. 9 shows a perspective view of an expanded conventional
stent;
FIG. 10 shows a perspective view of an assembled collapsed sleeve
carrying stent;
FIG. 11 shows a perspective view of an assembled expanded sleeve
carrying stent;
FIG. 12 shows a mechanical schematic diagram of a particular
embodiment of the invention;
FIG. 13 shows a mechanical schematic diagram of a particular
embodiment of the invention;
FIG. 14 shows a mechanical schematic diagram of a particular
embodiment of the invention;
FIG. 15 shows a perspective view of a strut as in FIG. 5 without
the interlocking mechanism;
FIG. 16 shows a mechanical schematic diagram of a particular
embodiment of the invention;
FIG. 17 shows a mechanical schematic diagram of a particular
embodiment of the invention;
FIG. 18 shows a mechanical schematic diagram of a particular
embodiment of the invention;
FIG. 19 shows a mechanical schematic diagram of a particular
embodiment of the invention;
FIG. 20 shows a perspective view of a particular embodiment of the
present invention;
FIG. 21 shows a rod-shaped strut which is used in the embodiment
shown in FIG. 20;
FIG. 22 shows a front elevational view of the embodiment shown in
FIG. 20;
FIG. 23 mechanical schematic diagram showing the positioning of a
strut and the sleeve an alternative embodiment of the
invention;
FIG. 24 mechanical schematic diagram showing the positioning of a
strut and the sleeve an alternative embodiment of the
invention;
FIG. 25 mechanical schematic diagram showing the positioning of a
strut and the sleeve an alternative embodiment of the
invention;
FIG. 26 is a mechanical schematic diagram showing the positioning
of a strut and the sleeve in an alternative embodiment of the
invention; and
FIG. 27 is an end view of FIG. 26.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, FIG. 1 illustrates the fully assembled
sleeve carrying stent, generally designated 10. The device is
composed of a plurality of elongated struts 12 loosely connected to
a conventional stent apparatus, generally designated 14. The struts
12 are positioned in a parallel fashion in a radially spaced manner
around the body of the stent. The structure further comprises a
luminal sleeve, preferably a collagen sleeve, generally designated
16, positioned on the opposite side of the stent wall as that of
the struts 12. The ends 17 of the sleeve 16 are folded over the
outside of the stent open ends 15 and are firmly attached to the
ends of the struts 12.
FIG. 2 illustrates a conventional stent 14 that can be used in the
present invention. Stents that can be utilized in the preferred
embodiment should have some kind of openings or slots 20 along the
body of the stent to facilitate the loose interlocking mechanism 22
between the struts 12 and the stent 14. The stent in FIG. 2
demonstrates an acceptable conventional stent due to its multiple
slots 20 incorporated in the wall of the stent. A conventional
stent usually is cylindrical in shape having open ends, an inner
wall and an outer wall. The present invention can utilize a variety
of conventional scents that are radially expandable, whether
self-expandable or expanded by some means. Typically, a balloon is
used for expansion.
FIGS. 3-6 illustrate a preferred structure of the struts 12. The
middle of a strut forms a depression 30 or a slight dip to allow
for the interlocking mechanism 22 with the slots 20 of the stent
14. Two tabs 32 protrude perpendicularly from the depressed area 30
and are utilized in the interlocking mechanism preventing the
struts 12 from separating from the stent 14. Barbs 34 are located
on the surface of the struts 12 at both ends and are used to secure
the ends of the luminal sleeve 17 to maintain tension of the sleeve
16. In the most preferred embodiment there are three struts and the
ends of the struts further comprise rounded radial perpendicular
members 36 that enhance the cylindrical nature of the device as
demonstrated in FIG. 6 and aid in guiding the luminal sleeve 16
over the ends of the struts 12 to be secured by the barbs 34. The
struts are arranged around the wall of the stent in a equidistant
radially spaced fashion as shown in FIG. 6.
The luminal sleeve 16 is cylindrical in shape and can be made from
a variety of biocompatible material, depending upon the intended
use. A luminal collagen sleeve is an example of such possibilities
and is the focus of this invention. Other sleeve compositions may
include polytetrafluoroethylene, polyesters, such as dacron.RTM.,
polyurethanes and silicones.
The sleeve in one particular embodiment is positioned inside of the
stent 14 with the ends 17 of the sleeve 16 extending out toward the
ends of the stent, folded over the ends of the struts and secured
by the barbs 34 as shown in the sectional view of FIG. 7. The
collagen sleeve 16 is not connected at all to the stent, allowing
the stent 14 to move independently between sleeve 16 and the struts
12, the stent and the struts being loosely interlocked near the
center of the stent.
In an alternative embodiment the struts would be positioned on the
inside of the stent wall and the sleeve would be positioned on the
outside of the stent wall or totally around the stent as
illustrated by the mechanical schematic diagram of FIG. 12, which
shows an end spatial relationship view of the embodiment. Still
another embodiment would be one in which the struts and the sleeve
are positioned on the same side of the stent wall, maintaining the
floating interlocking mechanism between the struts and the stent as
illustrated by the mechanical schematic diagram of 13 and 14, which
show end spatial relationship views of the embodiment. The
positioning of the particular parts is generally not important, as
long as the sleeve is secured by the struts to maintain tension and
to prevent shortening of the sleeve, and the stent is allowed
longitudinal independent movement.
The configurations mentioned above may also be made without the
interlocking mechanism between the struts and the stent 22. In this
case the struts 12 do not have the depression 30 or tabs 32, as
shown in FIG. 15. The arrangement of the sleeve and the struts are
such that the stent is sandwiched and thus held substantially in
place throughout the procedure. FIGS. 16 and 17 illustrate this
particular embodiment by showing spatial relationship end views.
FIG. 16 shows an embodiment of the invention wherein the struts are
on the outside of the stent wall and the sleeve is on the inside.
FIG. 17 shows an embodiment of the invention having the opposite
configuration.
FIGS. 18 and 19 demonstrate the configuration of still another
embodiment, wherein the sleeve and the struts are on the same side,
the outside, of the stent wall and there is no interlocking
mechanism. The sleeve and struts are carried by stent to the target
area. As the stent radially expands and shortens, the sleeve also
radially expands, but stays constant in terms of length.
Another embodiment is illustrated by FIGS. 20-22. In this
embodiment the struts are rod-shaped 40 and are incorporated in the
sleeve 42, the sleeve being created to have adequate thickness to
enclose the rod-shaped struts. The stent 14 is positioned inside
the sleeve/struts combination as shown in the perspective view of
FIG. 20 and the spatial relationship end view of FIG. 22.
In the present invention it is not required that the struts be
parallel nor straight. The struts may be curved as shown in FIG.
23, angled to form an apex as shown in FIG. 24, angled across the
body of the stent either on the inside or the outside of the sleeve
as shown in FIG. 25 or they may be diagonally positioned on the
inside of the stent wall from one end to the other as shown in
FIGS. 26 & 27. The basic functional requirement is that the
struts urge the sleeve longitudinally outward.
The importance of the present invention is the independent movement
of the stent without adversely affecting the sleeve and the
maintaining of tension and support of the sleeve. The exact
positioning of the parts is dictated by the purpose for which the
device is to be used.
The conventional carrier stent 14 can be collapsed as shown in FIG.
8 enabling it to be inserted into the targeted area by way of an
insertion device such as a catheter. In the collapsed state, the
stent has a diameter of d and a length of e. After being positioned
in the target lumen the stent may be expanded via balloon catheter
or self-expansion as shown in FIG. 9, changing the stent in length
and diameter urging the collagen sleeve against the vessel wall. In
its expanded form the stent has a diameter d' and a length e'. This
change in length is the focus of the problem in prior collagen
carrying stents. As the stent expands it shortens in length and
thus wrinkling the sleeve or even tearing the sleeve due to the
abrasive forces. In the present invention the stent is able to move
independent of the sleeve preventing it from affecting the tension
in the sleeve.
FIGS. 10 and 11 illustrate the expansion of the stent 14 with the
sleeve 16 and the struts 12 incorporated. FIG. 10 shows a collapsed
stent having length e and a diameter d with three struts
interlocked 22 to the outside of the stent 14, and with a sleeve 16
positioned on the inside of the stent 14. The ends of the sleeve
are folded over the ends of the struts and secured by the barbs on
the ends of the struts. As the stent radially expands to diameter
d' and its length shortens to e' as shown in FIG. 11 the length of
the sleeve 16 remains constant and the struts 14 maintain constant
tension on the sleeve. The stent 14 moves independent of the struts
and the sleeve, preventing the movement of the stent 14 from
adversely affecting the sleeve 16. The struts move out radially
with stent, but do not shorten, maintaining tension and support of
the sleeve.
As shown, these luminal collagen sleeves can be combined with
conventional luminal stents to repair and support damaged bodily
vessels. The collagen sleeve incorporates a non-thrombogenic
surface and promotes growth of endothelial cells, and can be used
as a reservoir or point of attachment for therapeutic agents. As
the sleeve carrying stent expands to support the targeted lumen,
the collagen sleeve comes in contact with the inner surface of the
luminal wall. The contact allows cellular growth between the wall
of the lumen and the collagen sleeve forming a bio-compatible
vascular prosthesis. In time, the sleeve and stent are incorporated
into the wall of the lumen reinforcing and sealing the vessel,
allowing for normal blood flow and bodily acceptability.
Essentially the present invention is a vascular prosthesis of
improved biocompatability. The improvement is in the delivery of
the sleeve. The present design allows the sleeve to be delivered
fully extended without any wrinkles in the sleeve due to the
shortening of conventional carrier stents. The present invention
allows for uniform growth and smooth blood flow through the device.
The struts maintain the length of the sleeve enabling the
prosthetic device to fully span the targeted problem area. This
enables the user to take advantage of the entire length of the
collagen sleeve, allowing location of the sleeve in a more
predictable manner.
The above disclosure is intended to be illustrative and not
exhaustive. These examples and description will suggest many
variations and alternatives to one of ordinary skill in this art.
All these alternatives and variations are intended to be included
within the scope of the attached claims. Those familiar with the
art may recognize other equivalents to the specific embodiments
described herein which equivalents are also intended to be
encompassed by the claims attached hereto.
* * * * *